To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Background pattern originally a PNG drawn in Paint.net
Source Firkin
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
Prismatic Groovy Concentric Background 3
Source GDJ
A background pattern with a look of rough fabric.
Source V. Hartikainen
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
A seamless background of warped stripes on paper.
Source V. Hartikainen
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ